Extract of asplenium nidus l.

ABSTRACT

An extract of  Asplenium nidus  L. includes pyropheophorbide a methyl ester (C 34 H 36 N 4 O 3 ), pheophorbide a methyl ester (C 35 H 36 N 4 O 5 ), 1-linleoyl-3-linolenoyl-glycerol (C 39 H 66 O 5 ), 1-linleoyl-2,3-dipalmitoyl-rac-glycerol (C 53 H 98 O 6 ) and 1,3-dipalmitoyl-sn-glycerol (C 35 H 68 O 5 ). The extract of  Asplenium nidus  L. is obtained by using a method including steps of: solvent extraction, using an solvent to extract an  Asplenium nidus  L. sample and to obtain an extract, with a w/v ratio between the solvent and the  Asplenium nidus  L. sample being 50-60 mg/ml; and column chromatography, fractionating the extract with water and ethanol as eluent to obtain several fractions including fraction a to fraction i, and further evaporating and lyophilizing fraction b, c, d or their combination to obtain an extract of  Asplenium nidus  L.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention generally relates to an extract of herbal and,more particularly, to an extract of Asplenium nidus L. apt to treat ofprostate diseases.

2. Description of the Related Art

Prostate, located around bladder outlet and surrounded by urethra, is apart of male's reproductive system.

Benign prostate hyperplasia (BPH) refers to hyperplasia of prostatestromal and epithelial cells, and generally occurs on male in fifty,usually resulting in the formation of large, fairly discrete nodules inthe periurethral region of the prostate. Progress of the benign prostatehyperplasia is unknown so far. Instead, it is believed androgens(testosterone and related hormones) and ages play a permissive role inthe occurrence of the benign prostate hyperplasia. When suffering fromthe benign prostate hyperplasia, enlargement of prostate will compressthe urethral canal to cause partial or sometimes virtually completeobstruction of the urethra, and thus, interfering with normal flows ofurine and leading to voiding dysfunctions, such as interruption,urorrhagia, incontinence and residual urine. Seriously, it may also leadto uremia or renal failure. Although benign prostate hyperplasia may notincrease incidence to prostate cancer, it usually causes false positivein the diagnosis of prostate cancer due to similar symptoms among eachother, and accordingly deferring a preferable time for treatment, oraffecting patient's mood somehow.

A conventional therapy of benign prostate hyperplasia generally dependson surgery or drug, but primary on drug treatment due to the prognosisand risk of surgery. Conventional drugs for benign prostate hyperplasiainclude alpha adrenergic blockers, such as Minipress, Dibenyline,Hytrin, Doxaben, and Xatral, and hormone inhibitor. However, the saidconventional drugs may lead to some side effects, such as hypotension,incontinence, nasal congestion, fatigue, and sexual dysfunction, andeven lead to complications as cooperating with other drugs (medicinesfor common cold, cardiovascular disease, and hypertension, for example),bringing about unbearable illness to patients. Furthermore, in view ofresearches, it may increase the incidence to prostate cancer and breastcancer after taking the said drugs for a long-term.

Recently, traditional medicine (TM) and complementary and alternativemedicine (CAM) has getting popular and important in Europe and UnitedStates, and accordingly, traditional herbs having therapeutic effects onprostate diseases, including lycopene, pumpkin seeds, saw palmetto,Pygeum africana, and progesterone, are gradually reported and developed.However, most of the said herbs are limited in use due to theirinefficient effects (as an example, lycopene and pumpkin seeds beingless effective in the therapy of prostate disease), poor extraction rateor origins (saw palmetto and Pygeum africana being difficult to obtain,as being available in Africa, and coast of Atlantic and Caribbean only).Also, similar to the said drugs, the said traditional herbs will causesome side effects, stomach discomfort, nausea, constipation or diarrheacaused by saw palmetto (reference being available at:http://liaozhai.pujia.com/thread-500003-1.html) for instance. In such,the said traditional herbs are limited in practical use.

Hence, it is needed to provide a new herbal product, havingsignificantly therapeutic effects on prostate diseases, and capable ofbeing further developed in clinical therapy or prophylaxis of prostatediseases.

Asplenium nidus L. is a species of fern in the family Aspleniaceae,native to tropical southeastern Asia, eastern Australia, Hawaii,Polynesia, Christmas Island, India, and eastern Africa. RecentlyAsplenium nidus L. has been widely cultivated and developed in Taiwan.Generally, Asplenium nidus L. is commonly sold as house plants, being avegetable rich in various nutrients and dietary fibers, and also it hasbeen used locally in folk medicine to prevent from hypertension, asthma,diabetes, constipation and colorectal cancer. Yet, a therapeutic use ofAsplenium nidus L. on prostate diseases has not been well-studied andreported.

SUMMARY OF THE INVENTION

It is therefore the objective of this invention to provide an extract ofAsplenium nidus L., which comprises natural active substances against toandrogen, and is apt to treat of prostate disease.

It is therefore the further objective of this invention to provide anextract of Asplenium nidus L., capable of modulating the secretion ofandrogen. The said extract of Asplenium nidus L. is easy to obtain andto isolate, so that it can be further applied to pharmaceuticalindustry, as an active substance in medications or health products forprostate disease.

It is therefore the further objective of this invention to provide anextract of Asplenium nidus L., putting in use on therapy or prophylaxisof prostate disease.

An extract of Asplenium nidus L. comprises pyropheophorbide a methylester, pheophorbide a methyl ester, 1-linleoyl-3-linolenoyl-glycerol,1-linleoyl-2,3-dipalmitoyl-rac-glycerol and 1,3-dipalmitoyl-sn-glycerol.

The said extract of Asplenium nidus L. is obtained by using a methodcomprising: solvent extraction, by extracting a sample of Aspleniumnidus L. with a solvent, with a w/v ratio of the sample of Aspleniumnidus L and the solvent being 50-60 mg/ml, and obtaining an extract;column chromatography, by fractionating the extract using a silica gelcolumn chromatography and using water and ethanol as eluents to obtainseveral fractions, being fraction a to fraction i sequentially; andfurther evaporating and lyophilizing fraction c to obtain an extract ofAsplenium nidus L.

In the extract of Asplenium nidus L., fraction b is evaporated andlyophilized to obtain the extract of Asplenium nidus L.

In the extract of Asplenium nidus L., fraction d is evaporated andlyophilized to obtain the extract of Asplenium nidus L.

In the extract of Asplenium nidus L., the solvent is 95% alcohol.

In the extract of Asplenium nidus L., the solvent is water.

The said extract of Asplenium nidus L. is obtained by using the methodfurther comprising a step of selecting, by selecting the whole plant ofAsplenium nidus L. as the sample of Asplenium nidus L.

In the extract of Asplenium nidus L., the whole plant of Aspleniumantiquum Makino is selected as the sample of Asplenium nidus L.

In the extract of Asplenium nidus L., the whole plant of Asplenium nidusLinn is selected as the sample of Asplenium nidus L.

The said extract of Asplenium nidus L. is used on pharmaceuticalindustry as an active substance treated of prostate disease, with theprostate disease comprising benign prostate hyperplasia, prostate canceror prostatitis, with an effective amount of the extract of Aspleniumnidus L. is 10 to 50 mg/kg of body weight of a subject in need.

The said extract of Asplenium nidus L. is used on manufacture of healthproducts as an active substance treated of prostate disease, with theprostate disease comprising benign prostate hyperplasia, prostate canceror prostatitis, with an effective amount of the extract of Aspleniumnidus L. is 10 to 50 mg/kg of body weight of a subject in need.

BRIEF DESCRIPTION OF THE DRAWINGS

The patent or application file contains at least one drawing executed incolor. Copies of this patent or patent application publication withcolor drawing(s) will be provided by the Office upon request and paymentof the necessary fee.

The present invention will become more fully understood from thedetailed description given hereinafter and the accompanying drawingswhich are given by way of illustration only, and thus are not limitativeof the present invention, and wherein:

FIG. 1 is a diagram illustrating the chemical structure ofpyropheophorbide a methyl ester.

FIG. 2 is a diagram illustrating the chemical structure of pheophorbidea methyl ester.

FIG. 3 is a diagram illustrating the chemical structure of1-linleoyl-3-linolenoyl-glycerol.

FIG. 4 is a diagram illustrating the chemical structure of1-linleoyl-2,3-dipalmitoyl-rac-glycerol.

FIG. 5 is a diagram illustrating the chemical structure of1,3-dipalmitoyl-sn-glycerol.

FIG. 6 is a diagram illustrating an extracting method of an extract ofAsplenium nidus L. in a preferable embodiment of the present invention.

FIG. 7 is a diagram illustrating eluting fractions of an extract ofAsplenium nidus L. in a preferable embodiment of the present invention.

FIG. 8 is diagram illustrating another extracting method of an extractof Asplenium nidus L. in a preferable embodiment of the presentinvention.

FIG. 9 is a bar chart illustrating the level of PSA-Luc inhibition of anextract of Asplenium nidus L. in a preferable embodiment of the presentinvention.

FIG. 10 is another bar chart illustrating the level of PSA-Lucinhibition of an extract of Asplenium nidus L. in a preferableembodiment of the present invention.

FIG. 11 is a bar chart illustrating cell viability of WPMY-1 aftertreated with an extract of Asplenium nidus L. in a preferable embodimentof the present invention.

FIG. 12 is a bar chart illustrating cell viability of LNCaP aftertreated with an extract of Asplenium nidus L. in a preferable embodimentof the present invention.

FIG. 13 is a bar chart illustrating cell viabilities of WPMY-1 and LNCaPunder various dosage of an extract of Asplenium nidus L. in the presentinvention.

FIG. 14 a is a chart illustrating prostatic index in BPH mice undervarious dosage of an extract of Asplenium nidus L. in the presentinvention.

FIG. 14 b is a chart illustrating excretion of urine in BPH mice undervarious dosage of an extract of Asplenium nidus L. in the presentinvention.

FIG. 14 c is a chart illustrating water intake in BPH mice under variousdosage of an extract of Asplenium nidus L. in the present invention.

FIG. 15 is morphological aspects (i to vi, H & E staining; Masson'strichrome staining, vii to ix, x100) of the disease-free (i) & (vii),phenylephrine-stimulated (ii) and (viii), and samples-treated (iii: ANE;iv and v: Lo; vi and ix: Hi) ventral prostate in BPH mice under variousdosage of an extract of Asplenium nidus L. in the present invention.

In the various figures of the drawings, the same numerals designate thesame or similar parts. Furthermore, when the terms “first”, “second”,“third”, “fourth”, “inner”, “outer” “top”, “bottom” and similar termsare used hereinafter, it should be understood that these terms havereference only to the structure shown in the drawings as it would appearto a person viewing the drawings, and are utilized only to facilitatedescribing the invention.

DETAILED DESCRIPTION OF THE INVENTION

With reference to FIGS. 1 and 2, a preferred embodiment of the inventiondiscloses an extract of Asplenium nidus L. comprising pyropheophorbide amethyl ester (C₃₄H₃₆N₄O₃; as shown in FIG. 1), pheophorbide a methylester (C₃₅H₃₆N₄O₅; as shown in FIG. 2), 1-linleoyl-3-linolenoyl-glycerol(C₃₉H₆₆O₅, as shown in FIG. 3), 1-linleoyl-2,3-dipalmitoyl-rac-glycerol(C₅₃H₉₈O₆, as shown in FIG. 4) and 1,3-dipalmitoyl-sn-glycerol(C₃₅H₆₈O₅, as shown in FIG. 5) and the said extract of Asplenium nidusL. is capable of inhibiting the secretion of androgen, decreasinginflammatory and reducing incidence to prostate disease.

FIG. 6 shows an extracting method of the extract of Asplenium nidus L.of the preferable embodiment in the present invention, comprising stepsof solvent extraction S1 and column chromatography S2.

In the step of solvent extraction S1, a sample of Asplenium nidus L. isprepared and extracted with a solvent, with a w/v ratio of the sample ofAsplenium nidus L. and the solvent being 50-60 mg/ml, to obtain anextract, wherein the solvent is 95% alcohol.

In the step of column chromatography, the said extract is fractioned byusing a silica gel column chromatography, with water and alcohol beingeluents, to obtain several fractions, including fractions a to i byorder of elution, and then fractions b, c, d or their combination isselected, evaporated, and lyophilized to obtain the extract of Aspleniumnidus L. of the preferable embodiment of the present invention.

Precisely, elution in the step of column chromatography is carried outvia an automated middle-sized liquid chromatography-Flash LC, preferablywith reverse phase column C18, to achieve preferable extracting rate,followed by using eluents in various compositions to obtain severalfractions, as shown in FIG. 7. The several fractions comprisingfractions a, b, c, d, e, f, g, h, i by the order of elution aresuccessfully obtained. Finally, the fractions b, c, d or theircombination are selected, evaporated and lyophilized to obtain theextract of Asplenium nidus L. of the preferable embodiment in thepresent invention. The said eluents comprise alcohol and water mixedwith each other in a linear gradient, wherein a concentration of alcoholin the eluents varies from 70% to 100%.

With reference to FIG. 8, the extracting method of the extract ofAsplenium nidus L. of the preferable embodiment in the present inventionpreferably comprises a step of selection S3 before the step of solventextraction S 1, with the sample of Asplenium nidus L. being selected asa whole plant of Asplenium nidus L. (including roots), so that, anextract of Asplenium nidus L. having a great amount of active substanceis successfully obtained. Furthermore, the sample of Asplenium nidus L.is selected from a whole plant of Asplenium antiquum Makino or Aspleniumnidus Linn, preferably a whole plant of Asplenium nidus Linn includingroots. Since, Asplenium nidus Linn is commonly distributed andcultivated throughout Taiwan, throughout the year, it is easy to obtainthe sample of Asplenium nidus L. and further to use in the extractingmethod of the present invention. Also, the Asplenium nidus Linn is greenand organic vegetables, being free from contamination of pesticide andinsects, so that the food safety thereof can be guarantee.

It is demonstrated that the extract of Asplenium nidus L. has activesubstances (including pyropheophorbide a methyl ester, pheophorbide amethyl ester) ester, 1-linleoyl-3-linolenoyl-glycerol,1-linleoyl-2,3-dipalmitoyl-rac-glycerol and 1,3-dipalmitoyl-sn-glycerol) against androgen and inflammation. Therefore,the said extract of Asplenium nidus L. is capable of modulating thesecretion of hormone, and further controlling diseases caused by hormoneimbalance, such as prostate diseases (including benign prostatehyperplasia, prostate cancer and prostatitis), incontinence, androgenicalopecia and menopausal disorders.

Also, the extract of Asplenium nidus L. is easy to obtain and toisolate, capable of being used on pharmaceutical industry, as an activesubstance in medications or health products for the said disease, thesaid prostate diseases in particular. The extract of Asplenium nidus L.can be used individually, or in combination with pharmaceuticalacceptable vehicles, excipients, salts or other nutrients, being in acomposite. In addition, the extract of Asplenium nidus L. can be furthermanufactured into any oral type that is easy to take, such as pastil,capsule, powder, pill, solution, or fermented products. Yet, the extractof Asplenium nidus L. can be combined with other food products ordrinks, being manufactured into a more convenient type for taking.

For proving the extract of Asplenium nidus L. in the preferableembodiment of the present invention truly having ability againstandrogen, a serial of trial is demonstrated below. However, theapplication of the said extract of Asplenium nidus L. is not limited tothat.

In the present trial, the said extracting method is carried out byprocessing the step of selection S3, the step of solvent extraction S 1,and the step of column chromatography S2 sequentially, with the sampleof Asplenium nidus L. being extracted by using 95% alcohol (being thesolvent), followed by eluting via the automated middle-sized liquidchromatography-Flash LC (with reverse phase column C18) to obtain 9fractions (including a to i). With reference to FIGS. 9 and 10, the 9fractions are collected and cultured with prostate cancer cell line22Rv/103E respectively, or co-cultured with a mix of the prostate cancercell line 22Rv/103E and stromal myofibroblast-WPMY-1 respectively, andthen activity against androgen of each fraction is determined.

In view of FIGS. 9 and 10, fractions b, c, and d all show significantinhibition either when they are cultured with the prostate cancer cellline 22Rv/103E respectively (see FIG. 9), or are co-cultured with themix of the prostate cancer cell 22Rv/103E and the stromalmyofibroblast-WPMY-1 (see FIG. 10), and particularly in a dose-dependentmanner.

In FIGS. 11 and 12, cell viability of the stromal myofibroblast-WPMY-1and prostate cancer cell line-LNCaP are demonstrated after culturingwith the 9 fractions respectively. The stromal myofibroblast-WPMY-1 andthe prostate cancer cell line-LNCaP are cultured with the 9 fractionsrespectively for 48 hours. After that, the stromal myofibroblast-WPMY-1and the prostate cancer cell line-LNCaP are dyed with SRB dye, and thenthe cell viability thereof is determined.

According to FIGS. 11 and 12, the fractions b, c, and d apparently haveinhibition on the growth of the stromal myofibroblast-WPMY-1 and theprostate cancer cell line-LNCaP in a dose-depended manner.

With reference to FIG. 13, the stromal myofibroblast-WPMY-1 (1) and theprostate cancer cell line-LNCaP (2) are cultured with a composite of thefractions b, c, and d, at various dosages respectively. After that, cellviabilities of the stromal myofibroblast-WPMY-1 and the prostate cancercell line-LNCaP are determined after the culturation, by using colonyformation assay. In FIG. 13, it is noted that the composite hasinhibition against the growth of the stromal myofibroblast-WPMY-1 (seeline 1) and the prostate cancer cell line-LNCaP (see line 2) in adose-depended manner. Also, a higher dosage of the composite, such 100μg/mL, will lead to the death of prostate cancer cells. In the presenttrial, the IC₅₀ of the composite on the stromal myofibroblast-WPMY-1 andthe prostate cancer cell line-LNCaP 11.63 μg/mL and 13.19 μg/mLrespectively.

Next, for proving the extract of Asplenium nidus L. in the preferableembodiment of the present invention truly having ability improvingagainst androgen, a serial of trial is demonstrated below. However, theapplication of the said extract of Asplenium nidus L. is not limited tothat.

C57BL/6Jnarl male mice purchased from the animal center of the NationalLaboratory Animal Center (NLAC, Taiwan) are used in this experiment. Themice are housed in a SPF animal room of Agricultural BiotechnologyResearch Center, Academia Sinica, Taiwan with constant temperature of22° C. where is kept on a 12-hours light and 12-hours dark cycle.

BPH mice are induced by chronic a(1)-adrenergic stimulation (15 mg/kg ofbody weight of the mice) and daily subcutaneous (sc) injection ofphenylephrine (PE) 5 days/week for five weeks. Furthermore, the BPH miceare treated with different doses of the extract of Asplenium nidus L. ofthe invention. Prostate index (PI, ventral prostate wet weight/mouseweight), urine excretion and water intake of the BPH mice are recordedin FIGS. 14 a, 14 b and 14 c. Moreover, the BPH mice are sacrificed andmorphological aspects of ventral prostate are shown in FIG. 15.

As shown in FIG. 14 a, compared with group control, group PE (treatedwith phenylephrine) has a significant increased PI value indicating theenlargement of prostate. The group PE excretes a significantly lowerlevel of urine and an amount of water intake of group PE issignificantly decreased over the group control. On the other hand, ingroup ANE (treated with ethanolic extract of Asplenium nidus L. withoutstep of column chromatography, 100 mg/kg of body weight/day), group Hi(treated with the extract of Asplenium nidus L. of the invention, 50mg/kg of body weight/day) or group Lo (treated with the extract ofAsplenium nidus L. of the invention, 10 mg/kg of body weight/day), thePI, urine excretion and water intake return to the normal level (p<0.01,vs. PE group). The group Hi has a preferable effect if the PI, urineexcretion and water intake (as shown in FIGS. 14 a, 14 b and 14 c). As aresult, the extract of Asplenium nidus L. of the invention is capable ofimproving BPH phenomenon.

The groups control, PE, ANE, Lo and Hi are sacrificed andHematoxylin-eosin staining (H&E staining) and Masson's trichromestaining of ventral prostate are preformed. In the H&E staining,compared with the group control, symptom of epithelial hyperplasiaoccurred in the group PE and the luminal areas of the ducts aredecreased, suggesting a compression of secretory gland (as shown in FIG.15-ii). The groups ANE, Lo and Hi are improved in the symptom ofepithelial hyperplasia (as shown in FIG. 15-iii, iv and vi). As shown inFIG. 15-vii-xi, collagen distributions of each group are shown in theMasson's trichrome staining The group control (FIG. 15-vii) shows higherarea of collagen (blue area, yellow arrows) and reticular fibers in thestromal region (orange arrows) than the group PE (FIG. 15-viii). Treatedwith the extract of Asplenium nidus L. of the invention (the group Hi)presents the restoration of collagen area and reticular fibers (FIG.15-ix).

Therefore, the extract of Asplenium nidus L. of the invention is capableof improving PE-indued BPH phenomenon, increasing urine excretion andfurther improving the pathological characteristics of BPH. The extractof Asplenium nidus L. of the invention can be used as an activesubstance in a form of drug or healthy product treating of prostatedisease.

Further, a practical example of the said extract of Asplenium nidus L.is provided below. However, the practical use of the said extract ofAsplenium nidus L. is not limited to that.

In the present trial, the said extracting method is carried out byprocessing the step of selection S3, the step of solvent extraction S 1,and the step of column chromatography S2 sequentially, to extract thesample of Asplenium nidus L. and to obtain the extract of Aspleniumnidus L. With reference to Table 1, the obtained extract of Aspleniumnidus L. is given to 88 patients (in various age groups) that sufferfrom various prostate diseases (including benign prostate hyperplasia,prostate cancer or prostatitis). Obviously, the extract of Aspleniumnidus L. is sufficient to be used on the therapy of benign prostatehyperplasia, prostate cancer and prostatitis, with symptoms of urinationbeing improved in 2-4 weeks in average and without leading to any sideeffects.

Generally, one of primary symptoms of benign prostate hyperplasia isurorrhagia and nocturn. However, with treatment of the said extract ofAsplenium nidus L., frequencies of urophagia and nocturnal enuresis onpatients are dramatically reduced till the same as normal. Moreover,according to International Prostate Symptom Score (I-PSS), the said 88patients has around 20-30 points of improvement in 2-4 weeks. Incomparison with other commercial health products (comprising 6%lycopene), only 2-3 points of improvement can be achieved.

TABLE 1 Therapeutic Effects on 88 Patients Ages Effects Numbers 93~101Normal urination, do not need 1 further treatment 70~85 Normalurination, do not need 8 further treatment 45~80 Normal urination 69Normal urination, levels of PSA 2 reduce from 8~9.5 to 6.0 in a shorttime 55 Normal urination in three days 1 55~60^(a) Urination being fullyrecovered in 2 1-3 days 60 Frequency and velocity of 1 urination turningnormal 70^(b) A great improvement on prostate 1 60~70^(c) Fullyrecovering in 2 months 3 ^(a)Patients having urinary tract adhesions(atypical symptom after prostate cancer surgery) after laser surgery.Urinary tract adhesions will last several months, and a general drugthereof is α-blocker. Instead, the extract of Asplenium nidus L. of thepreferable embodiment in the present invention fast response to affectparts, effectively improving symptoms of urinary tract adhesions. ^(b)Aprostate cancer patient ^(c)Patients of benign prostatic hyperplasia

In summary, the extract of Asplenium nidus L. in the preferableembodiment of the present invention has natural active substancesagainst androgen, and therefore, the said extract of Asplenium nidus L.is sufficient to be used on the therapy of diseases caused by hormoneimbalance, prostate diseases (including benign prostate hyperplasia,prostate cancer and prostatitis) in particular. Also, the said extractof Asplenium nidus L. will not lead to any side effects to patients. Thesaid extract of Asplenium nidus L. is easily to obtain via a convenientextracting method, and which is capable of being further applied totherapy or prophylaxis of the prostate disease, as an active substancein medications or health products thereof, to improve males' prostateissues.

Although the invention has been described in detail with reference toits presently preferable embodiments, it will be understood by one ofordinary skill in the art that various modifications can be made withoutdeparting from the spirit and the scope of the invention, as set forthin the appended claims.

1. An extract of Asplenium nidus L. comprising: pyropheophorbide amethyl ester; pheophorbide a methyl ester;1-linleoyl-3-linolenoyl-glycerol;1-linleoyl-2,3-dipalmitoyl-rac-glycerol; and 1,3-dipalmitoyl-sn-glycerol.
 2. The extract of Asplenium nidus L. as claimedin claim 1, wherein the extract of Asplenium nidus L. is obtained byusing a method comprising: extracting a sample of Asplenium nidus L.with a solvent, with a w/v ratio of the sample of Asplenium nidus L. andthe solvent being 50-60 mg/ml, to obtain an extract; fractionating theextract using a silica gel column chromatography and using water andethanol as eluents to obtain several fractions being fraction a tofraction i sequentially; and evaporating and lyophilizing fraction c toobtain an extract of Asplenium nidus L.
 3. The extract of Aspleniumnidus L. as claimed in claim 2, wherein, in the evaporating andlyophilizing, fraction b is evaporated and lyophilized to obtain theextract of Asplenium nidus L.
 4. The extract of Asplenium nidus L. asclaimed in claim 2, wherein, in the evaporating and lyophilizing,fraction d is evaporated and lyophilized to obtain the extract ofAsplenium nidus L.
 5. The extract of Asplenium nidus L. as claimed inclaim 2, wherein the solvent is 95% alcohol.
 6. The extract of Aspleniumnidus L. as claimed in claim 2, wherein the solvent is water.
 7. Theextract of Asplenium nidus L. as claimed in claim 2, wherein the sampleof Asplenium nidus L. is a whole plant of Asplenium nidus L.
 8. Theextract of Asplenium nidus L. as claimed in claim 7, wherein a wholeplant of Asplenium antiquum Makino is selected as the sample ofAsplenium nidus L.
 9. The extract of Asplenium nidus L. as claimed inclaim 7, wherein a whole plant of Asplenium nidus Linn is selected asthe sample of Asplenium nidus L.
 10. A method of treating prostatedisease comprising: administrating an active amount of the extract ofAsplenium nidus L. as claimed in claim 1 to a subject in need fortreating of prostate disease.
 11. A method of treating prostate diseaseas claimed in claim 10, wherein the extract of Asplenium nidus L. is inthe form of a health product treating of prostate disease.
 12. Themethod of treating prostate disease as claimed in claim 10, wherein theprostate disease comprises benign prostate hyperplasia, prostate cancerand prostatitis.
 13. The method of treating prostate disease as claimedin claim 11, wherein the prostate disease comprises benign prostatehyperplasia, prostate cancer and prostatitis.
 14. The method of treatingprostate disease as claimed in claim 10, wherein an effective amount ofthe extract of Asplenium nidus L. is 10-50 mg/kg of body weight of thesubject in need.
 15. The method of treating prostate disease as claimedin claim 10, wherein an effective amount of the extract of Aspleniumnidus L. is 50 mg/kg of body weight of the subject in need.